Don’t Look Now, But. . .

Quarterly profits and revenue at big American companies are poised to decline for the first time since the recession, as some industrial firms warn of a pullback in spending.

From railroads to manufacturers to energy producers, businesses say they are facing a protracted slowdown in production, sales and employment that will spill into next year. Some of them say they are already experiencing a downturn.

“The industrial environment’s in a recession. I don’t care what anybody says,” Daniel Florness, chief financial officer of Fastenal Co., told investors and analysts earlier this month. A third of the top 100 customers for Fastenal’s nuts, bolts and other factory and construction supplies have cut their spending by more than 10% and nearly a fifth by more than 25%, Mr. Florness said.